"Dillinger is a cloud-enabled, mobile-ready, offline-storage, AngularJS powered HTML5 Markdown editor."
So this is the official description, I'm going to make one more user-friendly for those of us who are not totally tech-savvy. Dillinger is a mix between Word and Notepad (figuratively!), it's easy to use like Notepad and can be as useful as Word for the Markdown format.
You'll have to manually check for your spelling. (Or you can export your formatted text on an editor with spell checking enabled).
I did not think about it first time but there are no ads. Like none. This is, I think, very nice for a free tool.
I guess the creator can only speak of this tool better than me :
The overriding design goal for Markdown's formatting syntax is to make it as readable as possible. The idea is that a Markdown-formatted document should be publishable as-is, as plain text, without looking like it's been marked up with tags or formatting instructions.
To sum up everything, Dillinger is
It can also be considered too light, but in fact, considering the Markdown format, it features everything needed to write a post on Steemit.
From now on, you'll have no excuse if your posts aren't formatted in Markdown!